|Sweet face on a dusky blue groundstreak|
I thought it might be instructive to go through key field markings. For this purpose, I searched through my back catalog and pulled images of five different species of hairstreak I've observed here in Texas. The subjects I've selected include three relatively similar-looking hairstreaks (the dusky blue groudstreak, the gray hairstreak, and the mallow scrub hairstreak) and two more distinctive hairstreaks (the great purple hairstreak and the silver banded hairstreak).
|A gray hairstreak (Strymon melinus)|
|Dusky blue groundstreak (Calycopis isobeon)|
|Mallow scrub hairstreak (Strymon istapa)|
Remember when I wrote about the uncluttered wings of the gray? The mallow scrub hairstreak is most definitely messy. There's a whole host of scribbles and bands in white and dark gray after the post-medial line. There's also minimal red on the eye-spots. Lastly, look at the front part of the hindwing and note the two dark gray spots. These two spots before the hindwing's band distinguish this hairstreak from all others. Like its con-generic the gray hairstreak, the mallow scrub hairstreak's caterpillars feed on mallows. This species is confined to the southern-most portions of the United States.
Another important thing to remember when identifying hairstreaks is that sometimes they don't have tails. The entire purpose of the eye-spotting and enticing tails on their hindwings is to encourage birds to take a nip there instead of other, more critical, areas. Many species of hairstreak even twitch and fidget their tails such that they resemble antennae.
|Silver banded hairstreak (Chlorostrymon simaethis)|
|Great Purple Hairstreak (Altides halesus)|
Obviously, this butterfly is quite distinct from most hairstreaks. However, the tells are still there. Like other hairstreaks, Great purples are petite with thin little tails, in contrast to the thick, chunkier tails on swallowtail butterflies. They also tend to sit with their wings folded, instead of spread to catch the sunlight.
In summary, many small butterflies with eye-spots and thread-like tails on their hindwings are in the Theclinae sub-family. After you have narrowed your search to this particular group, sorting through your options to get to species will probably require a combination of eye-spot characteristics, wing band size and coloration, and location. Good luck!
|A silver-banded behind|